-So in the original Call of Duty 2, a weapon has one firing sound for when the player fires it, and the exact same one for when the AI (A character or a soldier in the game) fires it. I changed that to having two sounds for each weapon some time ago, one for the player (stereo), and one for the AI (mono). Now, I have changed that too, it sounds very nice, there are 3 sounds for each weapon, a stereo one for the player, the same sound but mono for the AI at close range, and a mono one for when the AI fires it from far away. Let me explain it this way, sound A is for the AI at close range, sound B is for the AI at long range, when the AI fires a weapon, at close range, you can hear sound A and a bit of sound B, when the AI is far away and firing a weapon, you can only hear sound B, nothing of sound A. When you fire your weapon, you will hear a sound, when the AI fires the same weapon close to you, at least at a certain distance from you, you will hear the exact same sound for when you fire it, but when the AI is far, you will instead hear a distant sound. Some example of this could be Medal of Honor Airborne or Call of Duty 5 (more on medal of honor airborne), these games do this same thing I'm doing with the gun sounds. If you have any question or want to ask me how I managed to do this, just send me a message.
When you fire your weapon, you can hear the impact of a shell hitting the ground next to you, for this, I have not mixed the sound of the shell impact with the weapon firing, I have used the sound alias to make layers of sounds so the shell impact is a separate sound file, so we can use different shell sounds, you will not hear the same shell impact all the time, and when you fire multiple bullets with your SMG, or LMG, you can hear multiple shells falling to the ground.
The shell impact sound has been calculated exactly when to sound, so if when you fire your weapon you look at the shells falling, you will know that I had to sync the shell impact sound with the shell effect, exactly when the shell hits the ground, the sound will play. It has been calculated.